In October 2005, five autonomous vehicles successfully completed the “Grand Challenge” of the United States Defense Department's Advanced Research Projects Administration (DARPA), a competition requiring fully robotic vehicles to traverse a course covering more than one hundred miles. These vehicles were outfitted with robotic control systems in which a bank of computers control all of the operational systems of the vehicle, such as the steering, braking, transmission, and throttle, subject to autonomous decisions made by programs on board the vehicle, without human intervention on the course itself.
While the designers and builders of these vehicles have made an impressive accomplishment, the vehicles themselves were converted into special-purpose robots. There is no requirement in the competition for the vehicles to also be drivable by an operator, so only a few were. Even those that were drivable were not necessarily drivable in an ordinary manner. For example, a steering wheel on such a vehicle might still be turned by a human, but would encounter unnatural and sometimes dangerous resistance from a still-attached robotic actuator. While it is known that some of the vehicles were driven to the site on each day of competition, none are known to have been equally capable as autonomous vehicles and as manually driven vehicles. None were safe both in an autonomous role and in a manual role—the course was cleared of all spectators, and passengers were not allowed during autonomous operation. None had much, if any, provision for considering how an operator may safely and naturally interact with the vehicle.
With respect to switching between autonomous and manual use, robotic conversion of a vehicle can result in a conversion from conventional cabled and hydraulic control (direct mechanical control) to indirect control systems referred to as drive-by-wire systems. In drive-by-wire systems an actuator, such as an electric motor or hydraulic cylinder, applies throttle, braking, and/or steering input. These drive-by-wire systems do not have a connection to an operable mechanical control for ordinary driving (such as a lever, pedal, or steering wheel directly operated by cable tension or hydraulic lines). Converted vehicles become mostly or entirely drive-by-wire because they are usually not intended to be freely converted back to or switchable back to a manually driven configuration. Even if some operation systems can be operated by a driver, the conversion will use the intervening robotic software, electronics, and actuators (for example, the usual cabled accelerator may be disconnected, so that an operator may input a speed choice via a joystick or the like).
Retrofitted vehicles that use the intervening robotic software, electronics, and actuators in place of a disabled mechanical connection cannot be considered equally as capable as a conventional vehicle. They may be fully or partially disabled upon failure of robotic control systems. It may be difficult for passengers in such a vehicle to recover from accidents, e.g., removing the vehicle from a ditch if it becomes stuck. In extreme scenarios, such as military operations, a converted “one-way” vehicle lacks flexibility.
Trivial software problems may strand a drive-by-wire vehicle, at least because there are no mechanical connections for a driver to resume use of the basic operational systems of the vehicle. Known converted-to-robotics vehicles inherit this problem, and cannot be readily changed into fully manual vehicles at whim. There are other problems—for example, converted vehicles do not drive or perform in the manner of an unmodified vehicle from an operator's perspective. Simple activities, such as parking the vehicle in a garage or transport, may be more difficult than doing so in an ordinary manual vehicle, requiring complex programming or use of tele-operation.
To the extent that the prior art has contemplated some of the problems and opportunities associated with vehicles useful in both autonomous modes and manual modes, ergonomic and intuitive operation is usually not the primary problem addressed. For example, although it may be contemplated that one manual operation or another may be associated with switching between autonomous and manual modes, specific, ergonomically determined mode switching methods are not well defined. Moreover, specific mechanical accommodation for intuitive operator use of mode switching systems is rarely discussed.